title: Three-dimensional image formation under single-photon ultra-short pulsed illumination.
abstract: The major thrust of modern day fluorescence laser-scanning microscopy have been towards achieving better and better depth resolution embodied by the invention and subsequent development of confocal and multi-photon microscopic techniques. However, each method bears its own limitations: in having sufficient background fluorescence and photo-damage resulting from out-of-focus illumination for the former, while low multi-photon absorption cross-sections of common fluorophores for the latter. Here we show how the intelligent choice of single-photon ultrashort pulsed illumination can circumvent all these shortcomings by exemplifying the tiny spatial stretch of an ultrashort pulse. Besides achieving a novel way of optical sectioning, this new method offers improved signal-to-noise ratio as well as reduced photo-damage which are crucial for live cell imaging under prolonged exposure to light.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, UP - 208016, India.
authors.forename: Arijit Kumar
authors.initials: AK
authors.lastname: De
authors.forename: Debabrata
authors.initials: D
authors.lastname: Goswami
keywords: Fluorescence microscopy; confocal detection; multi-photon excitation; optical sectioning; pulsed illumination; second-harmonic generation; threshold detection; ultra-short pulses